Saturday, 28 August 2010

Bristol Parrots 1: Killer Clowns

“Clowns of the Snowline” is the commonest description of the first species in Bristol’s parrot collection that I am going to write about, the Kea, Nestor notabilis. It is appropriate that I start with this species, as it represents the earliest branch on the family tree of living parrots, together with some other New Zealand species, the Weka Nestor meridionalis, and the famous Kakapo, Strigops habrotila. These make up the family Nestoridae, together with the extinct Norfolk Island Kaka Nestor productus (extinct 1851). A fourth form of Nestor, the extinct Chatham Island Kaka, is not certainly a separate species and has not been scientifically described. Wekas are very similar to Keas, but are lowland rather than mountain birds.

Saturday, 21 August 2010

Butterflies of Bristol 14: These just in

No time for a full post this week - some new arrivals for our butterfly house though. In addition to these new species, we have the usual cast of characters - see previous posts on butterflies at Bristol.

The Malachite Siproeta stelenes

This beautiful luminous green and black butterfly is fairly large, about the size of a Red Admiral, and like all our butterflies originates from Costa Rica. (incidentally, check out the website of our supplier, El Bosque Nuevo for more information),

Malachite butterflies have a huge range extending from southern Texas and the tip of Florida, south to northern Brazil. The caterpillar feeds on plants of the Acanthaceae, a mainly tropical family which provides several housplants such as Fittonia, although the main foodplant appears to be Ruellia. They may lay on some of the houseplants planted as ground cover in the butterfly house. Like most nymphalid, the larva is covered with bristles. Adults are fond of roosting on the underside of leaves in low shrubs.

The Olivewing Nessaea aglaura

These butterflies have very distinctive green undersides to their wings, which provides camouflage. The upper sides are dark brown with sky blue diagonal streaks. Females have red spots on the center of the forewing.

They are usually found in primary forest up to 800m, where they spend a lot of time resting on low foliage up to 3m from the ground. They like to bask in sunshine, opening their wings to show their bright blue stripes, and are very fond of particular resting spots, to which they return if disturbed.

The eggs are laid on Alchornea or Plukunetia, which belong to the Euphorbiaceae, but I have found one report of them laying on stinging nettle in captivity.

Next week, normal service, starting with the "Clown of the Snowline", the Kea. Clowns may have a dark side however...
(Images from Wikipedia)

Saturday, 14 August 2010

Rodents of Bristol 9:The weirdest of them all

To draw this series on the rodents on show at Bristol to a close, I will finish with what is arguably the weirdest mammal (certainly the weirdest rodent) in the world, the Naked Mole Rat Heterocephalus glaber. Belonging to a sub-Saharan family of burrowing rodents, the Bathyergidae, Naked Mole Rats are confined to the horn of Africa from Kenya to the Sudan, where they can be locally common depending on the environment.

As you might guess from their range, they are essentially aridland animals, living almost entirely on the starchy tubers of desert plants, which provide all the water they need. Some of these tubers can be 60cm across, and the colony will feed on them for months or years. Quite often, when they finish they will use the hollow in the still living plant as a latrine site, thereby providing the plant with a fertilizer boost so they can return in a year or two’s time when it has regenerated.

Saturday, 7 August 2010

Rodents of Bristol 8: Returning ratty

As many people in the UK at least will know, Ratty in Wind in the Willows was actually a Water Vole, Arvicola terrestris (there is some dispute about the scientific name – it may be more properly described as A.amphibius). Once a familiar sight along canals and rivers, anywhere in Britain (including northern Scotland) where there is dense grass or reed next to water, the Water Vole has experienced a catastrophic drop in numbers in recent years. The main causes appear to be habitat destruction and even more the spread of American Mink, which have escaped or been released from fur farms (in some cases by animal rights activists). Unfortunately, Mink are far more successful predators of voles than native ones such as Otters, Barn owls and Grey Herons, and in fragmented habitats especially the voles cannot survive the predation pressure.

Monday, 2 August 2010

Rodents of Bristol 7: Pests and their relatives

On display in Twilight world the final section is devoted to animals found in close proximity to man, of which three are rodents – House Mouse, Brown Rat, and Black or Roof Rat. All these are among the most succesful of all mammals, owing to their adaptation to life alongside humans (and their food stores). All are causes of serious conservation problems wherever they have been taken, especially on islands, where they readily abandon human dependency and prey on local wildlife, especially birds and their eggs.